In 1967, Rolex changed the world of waterproof watches. . . again. The first Rolex Sea-Dweller (Ref. 1665) was the first production wristwatch featuring a helium escape valve. This is particularly useful for saturation divers, or divers who stay underwater (and/or under pressure) for extended periods of time. It’s crucial that saturation divers breathe a gas mixture that includes helium (as opposed to nitrogen). Helium is small enough to get past gaskets and into your watch, which is fine while the watch is under pressure. However, as it decompresses, the increasing volume can literally make your watch explode. The helium escape valve allows a purge of helium from your watch, preventing potential damage and/or explosions. In short, the helium escape valve is a pretty big technical achievement.
Most modern Rolex watches are products of slow and steady evolution: decades of small changes resulting in a nearly perfect purpose-built tool. The Rolex Sea-Dweller is no different. It was released more than a decade into the Submariner’s life, and is very similar to the brand’s flagship dive watch. The Sea-Dweller is more robust, and thus exhibits a slightly chunkier case. The 40mm 1665 features 610 meters of water resistance, the all new helium escape valve, and a date complication without a cyclops crystal. It was a monumental shift in the world of dive watches. The 1665 is nicknamed the “Double Red” due to its two lines of red text reading “Sea-Dweller Submariner 2000”. In 1977, these lines of red text were replaced with white, appropriately nicknaming the watch “Great White”.
The next year in 1978, Rolex released the new Sea-Dweller (Ref. 16660), also known as the “Triple Six”. This update doubled the depth rating to 1220 meters, adding a sapphire crystal and tweaking the helium escape valve. This new reference also saw an upgraded movement: the caliber 3035. One decade later, Rolex released the Sea-Dweller (Ref. 16600). This reference saw another movement upgrade to the caliber 3135, but remained 40mm in diameter. In 2008, the 16600 was replaced by the Deepsea Sea-Dweller (Ref. 116660). This 44mm behemoth has a depth rating of 3900 meters and a Cerachrom bezel. The late 2000’s is when most Rolex watches received the Cerachrom treatment: a welcome upgrade to collectors and enthusiasts. In 2014, Rolex released the gradient-dialed Deepsea D-Blue Sea-Dweller 116660 honoring James Cameron’s deep dive in the Mariana Trench. This was essentially a special edition of the 116660 – not much changed here. That same year, Rolex released the 40mm Sea-Dweller 116600 (yes, these reference numbers are horribly confusing). This Sea-Dweller is also known as the SD4000. The SD4000 was a sweet spot for many enthusiasts – all the modern spec with a wearable 40mm case. However, it was discontinued in 2017. That year, the SD4000 was replaced by the Sea-Dweller 126600, also known as the SD43. The SD43, as you may have guessed, has a 43mm diameter. It brings back the red “Sea-Dweller” text, as well as a cyclops date window for the first time in the model’s history.
The Rolex Deepsea Sea-Dweller (Ref. 116660) is a classic tool watch. Its large case (44mm) design fits its rugged, utilitarian spec sheet. It is a modern example of a historic tool: a product of decades of evolution. Everest’s Curved End rubber straps are tailor fit to the dimensions of the Rolex Deepsea Sea-Dweller (Ref. 116660), seamlessly hugging the case and lugs. Rubber excels as a strong, lightweight, waterproof strap material (just make sure your watch is waterproof too). Rubber isn’t just practical, it’s one of the most comfortable materials for a watch strap. If you like the sporty look, rubber is a great everyday option. It’s a welcome addition to any strap collection. If you’re looking for a new strap for your Rolex Deepsea Sea-Dweller (Ref. 116660), Everest bands are your best bet.